Ganguli et al.

Mild cognitive impairment is a cognitive state intermediate between normal cognitive aging and dementia. In a recent study published in the journal Neurology, Dr. Mary Ganguli and her colleagues examined the incidence of mild cognitive impairment in previously normal older adults and the associations of several premorbid vascular risk factors with incident mild cognitive impairment. Dr. Ganguli and her team studied an age-stratified random population-based cohort of over 1,900 non-institutionalized individuals aged 65 or older. These individuals were evaluated at baseline using several measures of vascular, metabolic, and inflammatory risk, and were assessed annually for cognitive and everyday function over a four-year period. Incidence rates were calculated for both cognitive (neuropsychological) and functional (Clinical Dementia Rating = 0.5) definitions of mild cognitive impairment. Since the same factors can increase risk both of cognitive impairment and of attrition from the study, the investigators adjusted for attrition bias by jointly modeling mild cognitive impairment and attrition.

Results of the study indicated that the incidence of mild cognitive impairment increased with age regardless of definition and did not vary by sex or education. In addition, several vascular risk factors (e.g. stroke, heart failure, diabetes, and waist-to-hip ratio) increased the risk of incident mild cognitive impairment, whether defined cognitively or functionally, but most were associated with nonamnestic mild cognitive impairment and a clinical dementia rating of 0.5. Light to moderate alcohol use appeared protective. This study demonstrates that controlling vascular risk factors may potentially reduce the incidence of mild cognitive impairment in older adults.